1. Field of the Invention
This invention relates to an apparatus for recording and reproducing an information signal and more particularly to a recording and reproducing apparatus including a tracking control device which enables a recording or reproducing head to accurately trace a recording track in which the information signal is recorded on the recording medium.
2. Description of the Prior Art
Generally a magnetic recording and reproducing apparatus of the class adapted for recording and reproduction of television signals (hereinafter called a VTR) is arranged to have video signals, etc. recorded and reproduced in and from tracks one after another with a rotary head scanning the magnetic surface of a recording tape askew at a given angle to the travelling direction of the tape.
In a two-head helical scanning type VTR, for example, tracks are formed in sequence, one track for each field as shown in FIG. 1 of the accompanying drawings. Further, while video signals are recorded in these oblique tracks, a control signal (hereinafter called the CTL signal) which is a reference signal for enabling these recording tracks to be accurately traced at the time of reproduction is recorded for every two fields, or for every frame, in a control track 2 (hereinafter called the CTL track) which is provided along one edge of a magnetic recording tape 1.
At the time of reproduction, therefore, two rotary heads accurately trace recorded tracks if capstan, etc. which are arranged to cause the magnetic tape to travel are controlled in such a way as to have the CTL signal reproduced at a predetermined phase relative to the rotation of the rotary heads.
Further, in the conventional insertive recording method, tape travel is controlled such that the CTL signal which has already been recorded is reproduced at a given phase relative to the rotary head rotating in synchronism with a video signal to be inserted, so that the above-stated video signal can be recorded while tracking control is being accomplished in the same manner as in reproduction. This ensures unimpaired continuity of the tracks even before and after an inserted scene or at a changing part from one scene to another, so that no vacillation will take place in a reproduced picture.
Various methods have been proposed with respect to insertive editing. The details of these editing methods are well known and therefore are omitted from description herein.
Home VTR technology has conspicuously advanced during recent years. Further, proposals have been made for various systems which are arranged to permit reduction in size of such VTR's or improvement in their recording density by superposing a pilot signal on a track to be scanned by a rotary head and by performing tracking control with the signal at the time of reproduction, so that a CTL track 2 or a CTL signal recording and reproducing head can be dispensed with.
An aural signal recording track 3 has conventionally been provided along an edge of the tape 1 on the side opposite to the CTL track 2. A system has been proposed which dispenses with a stationary aural signal recording head by FM modulating the aural signal and by recording it with a rotary head superposed on a video signal.
Such an apparatus that has no stationary head is, however, not desirable for the above-stated insertive recording as it requires additional provision of a CTL head for insertive recording.